/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package java.nio;

import com.google.gwt.corp.webgl.client.HasWebGLArray;
import com.google.gwt.corp.webgl.client.WebGLArray;
import com.google.gwt.corp.webgl.client.WebGLShortArray;

//import org.apache.harmony.nio.internal.DirectBuffer;
//import org.apache.harmony.luni.platform.PlatformAddress;

/**
 * This class wraps a byte buffer to be a short buffer.
 * <p>
 * Implementation notice:
 * <ul>
 * <li>After a byte buffer instance is wrapped, it becomes privately owned by
 * the adapter. It must NOT be accessed outside the adapter any more.</li>
 * <li>The byte buffer's position and limit are NOT linked with the adapter.
 * The adapter extends Buffer, thus has its own position and limit.</li>
 * </ul>
 * </p>
 * 
 */
final class DirectReadWriteShortBufferAdapter extends ShortBuffer implements HasWebGLArray {
//implements DirectBuffer {

    static ShortBuffer wrap(DirectReadWriteByteBuffer byteBuffer) {
        return new DirectReadWriteShortBufferAdapter((DirectReadWriteByteBuffer) byteBuffer.slice());
    }

    private final DirectReadWriteByteBuffer byteBuffer;
    private final WebGLShortArray shortArray;

    DirectReadWriteShortBufferAdapter(DirectReadWriteByteBuffer byteBuffer) {
        super((byteBuffer.capacity() >> 1));
        this.byteBuffer = byteBuffer;
        this.byteBuffer.clear();
        this.shortArray = WebGLShortArray.create(byteBuffer.byteArray.getBuffer(), 
        			byteBuffer.byteArray.getByteOffset(),
        			capacity);
    }

    // TODO(haustein) This will be slow
    @Override
    public ShortBuffer asReadOnlyBuffer() {
        DirectReadOnlyShortBufferAdapter buf = new DirectReadOnlyShortBufferAdapter(byteBuffer);
        buf.limit = limit;
        buf.position = position;
        buf.mark = mark;
        return buf;
    }

    @Override
    public ShortBuffer compact() {
        byteBuffer.limit(limit << 1);
        byteBuffer.position(position << 1);
        byteBuffer.compact();
        byteBuffer.clear();
        position = limit - position;
        limit = capacity;
        mark = UNSET_MARK;
        return this;
    }

    @Override
    public ShortBuffer duplicate() {
        DirectReadWriteShortBufferAdapter buf = new DirectReadWriteShortBufferAdapter(
        		(DirectReadWriteByteBuffer) byteBuffer.duplicate());
        buf.limit = limit;
        buf.position = position;
        buf.mark = mark;
        return buf;
    }

    @Override
    public short get() {
//        if (position == limit) {
//            throw new BufferUnderflowException();
//        }
        return shortArray.get(position++);
    }

    @Override
    public short get(int index) {
//        if (index < 0 || index >= limit) {
//            throw new IndexOutOfBoundsException();
//        }
        return shortArray.get(index);
    }

    @Override
    public boolean isDirect() {
        return true;
    }

    @Override
    public boolean isReadOnly() {
        return false;
    }

    @Override
    public ByteOrder order() {
        return byteBuffer.order();
    }

    @Override
    protected short[] protectedArray() {
        throw new UnsupportedOperationException();
    }

    @Override
    protected int protectedArrayOffset() {
        throw new UnsupportedOperationException();
    }

    @Override
    protected boolean protectedHasArray() {
        return false;
    }

    @Override
    public ShortBuffer put(short c) {
//        if (position == limit) {
//            throw new BufferOverflowException();
//        }
        shortArray.set(position++, c);
        return this;
    }

    @Override
    public ShortBuffer put(int index, short c) {
//        if (index < 0 || index >= limit) {
//            throw new IndexOutOfBoundsException();
//        }
        shortArray.set(index, c);
        return this;
    }

    @Override
    public ShortBuffer slice() {
        byteBuffer.limit(limit << 1);
        byteBuffer.position(position << 1);
        ShortBuffer result = new DirectReadWriteShortBufferAdapter((DirectReadWriteByteBuffer) 
        		byteBuffer.slice());
        byteBuffer.clear();
        return result;
    }

	public WebGLArray<?> getWebGLArray() {
		return shortArray;
	}
	

	public int getElementSize() {
		return 2;
	}

}
